I have a coolster 125cc that I just put a brand new wiring harness on it and it keeps blowing the fuse close to the battery! Well I decided to do a fuse bypass to see if I could see the problem and the ignition key keeps melting when the key gets turned on. I've ran the entire harness and there is no showing or cut wires everything is grounded I believe how it needs to be and I have no idea what can be causing this any ideas ? I'm completely stumped at this point 🤔

This is the burnt wire which I know needs changed but trying to figure out why it did this first

 

I have worked on one of these before and what was happening to me is when I put a new ignition in it the wires did not align up with the proper wire. This was causing it to blow fuses.

 

I would first split those melted wires, positive and the ground, because it will blow the fuse every time when you turn the key on.
Then I would change the fuse, and unhook all connectors, and then connect them one by one to check if the fuse will blow again, that would be the indicator of which component is causing the short circuit.